Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Quantas vendas tiveram uma posição de pico de 1 e uma certificação de 6x platina?
 ###Tabelas: CREATE TABLE title_holders_from_1973_until_1991 (title_holders_from_1973_until_1991_id AUTO_INCREMENT PRIMARY KEY, Year INT, Binibining Pilipinas-Universe VARCHAR, Binibining Pilipinas-International VARCHAR, Miss Maja Pilipinas VARCHAR, Binibining Pilipinas-Tourism VARCHAR, First runner-up VARCHAR, Second runner-up VARCHAR) CREATE TABLE list_of_the_most_populous_us_counties_sorted_according_to_the_mid-2011_official_estimate_by_the_uscb (list_of_the_most_populous_us_counties_sorted_according_to_the_mid-2011_official_estimate_by_the_uscb_id AUTO_INCREMENT PRIMARY KEY, Rank VARCHAR, County VARCHAR, State VARCHAR, Land area (km²) VARCHAR, Land area (mi²) VARCHAR, April 1, 2010 census VARCHAR, April 1, 2010 density (/km²) VARCHAR, April 1, 2010 density (/mi²) VARCHAR, July 1, 2010 official estimate VARCHAR, July 1, 2010 density (/km²) VARCHAR, July 1, 2010 density (/mi²) VARCHAR, July 1, 2011 official estimate VARCHAR, July 1, 2011 density (/km²) VARCHAR, July 1, 2011 density (/mi²) VARCHAR, Mid-2010 to mid-2011 change (Absolute) VARCHAR, Mid-2010 to mid-2011 change (%) VARCHAR, County seat or courthouse VARCHAR) CREATE TABLE year_by_year (year_by_year_id AUTO_INCREMENT PRIMARY KEY, Season VARCHAR, Coach VARCHAR, Conf. Record VARCHAR, Overall VARCHAR, Standings VARCHAR, Postseason VARCHAR) CREATE TABLE top_10_american_albums (top_10_american_albums_id AUTO_INCREMENT PRIMARY KEY, Rank INT, Artist VARCHAR, Album VARCHAR, Peak position INT, Sales INT, Certification VARCHAR) CREATE TABLE one_day_batting_statistics (one_day_batting_statistics_id AUTO_INCREMENT PRIMARY KEY, Player VARCHAR, Matches INT, Innings INT, Not Out INT, Runs INT, High Score VARCHAR, Average VARCHAR, Strike Rate VARCHAR, 100s INT)  
SELECT COUNT Sales FROM top_10_american_albums WHERE Peak position = 1 AND Certification = 6x platinum